Alarm system



M. T. SLIMAN Dec. 17, 1963 ALARM SYSTEM 2 Sheets-Sheet 1 Filed Aug. 13,1962 INVENTOR. Mama TJZ/MA/V BY W n m.

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ALARM SYSTEM Filed Aug. 13, 1962 2 Sheets-Sheet 2 17a 6 M P-1w? l2) k1}mmmfu,

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United States Patent 3,114,995 ALARM SYSTEM Michael T. Slimau, 826 W.Capitol Ave, West Sacramento, Calif. Filed Aug. 13, 1962, Ser. No.216,496 Claims. (Cl. 340-280) This invention relates to an alarm system,and has as its primary object the provision of a means whereby theremoval, or attempted removal of an electrical appliance such as atelevision set, a radio, a lamp, or any other normally connectedelectrical appliance, will cause a visual, audible, or other alarm to beactuated to indicate the potential removal of the appliance.

An additional object of the invention is the provision of an alarm ofthis character which may be concealed, or semi-concealed, in such manneras not to attract the attention of the potential thief and cause him totake steps to circumvent the alarm.

A further object of this invention is the provision of such an alarmwhich is contained within an electrical wallbox, and which is soarranged that tampering therewith to render the alarm inoperative isextremely difiicult.

Other objects reside in the combinations of elements, arrangements ofparts, and features of construction.

Still other objects reside in the provision of a device of thischaracter which is sturdy and durable in construc tion, reliable andeflicient in operation, and which is substantially automatic inoperation and requires a minimum of moving parts.

In the drawings:

FIGURE 1 is a fragmentary partially schematic view of the wall of a roomto be rented furnished showing the wallbox, and its connection with analarm system.

FIGURE 2 is a vertical cross-sectional view of one form of outlet boxembodying features of the instant invention.

FIGURE 3 is a plan view of the face plate of the outlet box takensubstantially along the line 3-3 of FIG- URE 2 as viewed in thedirection indicated by the arrows.

FIGURE 4 is a plan view of the face of the plug shown in FIGURE 2 takensubstantially along the line 22 of FIGURE 2 as viewed in the directionindicated by the arrows.

FIGURE 5 is a fragmentary sectional View taken substantially along theline 5--5 of FIGURE 2 as viewed in the direction indicated by the arrowsshowing certain of the parts in a different position of adjustment.

FIGURE 6 is a view similar to FIGURE 2 but showing a slightly modifiedform of construction.

FIGURE 7 is a view similar to- FIGURE 3 taken sub stantially along theline 77 of FIGURE 6 but showing a modified form of construction.

FIGURE 8 is a view similar to FIGURE 4 taken substantially along theline 88 of FIGURE 6 and showing the construction of the plug of FIGURE6; and

FIGURE 9 is a sectional view taken substantially along the line 9-9 ofFIGURE 6 as viewed in the direction indicated by the arrows.

Similar reference characters refer to similar parts throughout theseveral views of the drawing.

Having reference now to the drawings in detail, and more particularly toFIGURE 1, there is generally indicated at 19 a wall of a room of thetype which is rented furnished normally, such as a hotel room, aturnished room, a motel room or the like. The wall includes the usualfacing behind which are the studs 1-1, and is provided with anelectrical outlet box, generally indicated at 12, which is closed by aface plate 13 having a pair of female plugs therein as indicated at 14,the plugs being of the usual tw-o prong type and having a pair of slots15, for the reception of the prong 16 of an associated male plug 17.

The face plate is connected to the usual electrical outlet box 18 in theusual manner by a screw 19, except that in accordance with the instantinvention the screw 19 extends entirely through the box, and isconstructed of magnetic or electrically conductive material, rather thanthe brass screw which is sometimes used in this connection. A pair ofelectrical wires 20 extends from suitable junctions 21 exteriorly of thebox 18, and provide power for the appliance which is connected throughplug 17 and cord 22 to the source of electricity.

The alarm of the instant invention comprises a fixed contact member 25which is mounted on a supporting bracket 26 and a movable contact member27 which is mounted on a spring arm 28. Wires 29 and 30 extend fromcontacts 25 and 27, and comprise a part of an electrical alarm circuitwhich is energized when the contact 27 is moved into engagement with thecontact 25 in a manner to be more fully described hereinafiter. Thewires 2? and 3t extend interiorly of the wall to an opening 31, andthence along the baseboard 32 and beneath the carpet 33 to a secondopening 34, from which they extend to a suitable alarm box 35, which maybe the telephone junction box, as described in my co-pending applieationSerial No. 216,495, filed concurrently herewith.

The arrangement is such that as long as the contacts 27 and 25 areseparated no alarm is actuated, but that promptly upon the engagement ofcontact 27 with contact 25, a suitable audible, visual, or other alarmis sounded either adjacent or in the room carrying the outlet box, or ata remote point such as a switchboard.

Contacts 27 and 25 are normally maintained in spaced relation by thenormal resiliency of spring finger 28, unless closed by the dropping ofa heavy magnetic metal weight 44 Weight 46 is contained in a verticalsleeve 41 which is secured by means of a strap 4-2 to the rear wall ofoutlet box I3, and is held in its uppermost position by means of amagnetic charge induced in steel or conductive metal screw 19. Thecharge in magnetic screw 19 is induced by a permanent magnet 43 which iscontained in plug 17, plug 17 being normally of the three prong type,and the magnet 43 being inserted in place of the usual ground prong. Inthis illustrative embodiment of the invention the plug '17 is of such ashape that the magnet 43 directly engages the head of screw 19, and aslong as magnetic force is applied through screw 19 the steel or othermagnetic weight is retained in position against the screw 19, as shownin FIGURE 2. Removal of the plug 17, however, will immediately break themagnetic contact permitting weight 40 to drop forcing spring arm 28downwardly and engaging contact 27 with contact 25 to close the circuitand actuate the alarm.

permanent magnet 45 is positioned so that the wire 46 contacts screw 19,and the force thereof is suflicient to raise weight 40 to its uppermostposition.

FIGURES 6 to 9, inclusive, disclose a similar arrangement wherein a wall10 contains an outlet box 12 having a face plate 13 and a pair of femaleplugs 14a, which may be, if desired, of the three prong variety, butwhich in any event are set farther apart than the corresponding plugs14. Female plugs 14a are adapted to be engaged by a male plug 1711 whichis provided with male prongs 16a adapted to be inserted in the slots 15aof the female plugs or sockets 14a. In this modification a magneticscrew 19a serves to hold the plugs in related assembly.

The interior mechanism of the box 12 is identical to that previouslydescribed, and in consequence identical reference numerals are employedfor similar parts, with the exception of the screw 19a. When the screw1% is magnetized, in a manner to be more fully described hereinafter,the weight 48) is held in contact therewith, and when the magnetic forceis released, weight 4th drops to engage contacts 27 and 25 exactly as inthe previous modification.

However, in this form of the invention, because of the spacing of thefemale plugs 14a, or alternatively, because of the configuration of thethree prong plug 17a, mounted magnet 43a is not aligned with screw 1901.In order, therefore, to achieve magnetization of the screw 19, andconsequently, hold the weight 4%) in elevated position, a wire 50 islooped around the head of screw 1% and extended upwardly, as best shownin FIGURES 6 and 7, to a point where it will be readily contacted by thepermanent magnet 43a. In this manner the screw 1% is magnetized, and thesteel weight 40 is held closely thereagainst until plug 17a is removedfor any unauthorized purpose.

From the foregoing it will now be seen that there is herein provided animproved alarm system which accomplishes all the objects of thisinvention, and others, including many advantages of great practicalutility and commercial importance.

As many embodiments may be made of this inventive concept, and as manymodifications may be made in the embodiments hereinbefore shown anddescribed, it is to be understood that all matter herein is to beinterpreted merely as illustrative, and not in a limiting sense.

Iclaim:

1. An alarm system for preventing the unauthorized removal of anelectrical appliance, comprising a wall outlet box having a face plate,a magnetic screw securing said face plate to the box and extendtherethrough, at least one female socket carried by said box, a fixedcontact mounted on said box interiorly of the wall receptacle, a springarm above said fixed contact, a movable contact on said spring arm, analarm circuit actuable by engagement of said movable contact with saidfixed contact, a

magnetic Weight normally supported above said spring arm, a male plugconnected to an electrical appliance engageable in said female socket,magnetic means carried by said male plug, and means contacting saidmagnetic screw with said magnetic means when said male plug is insertedin said female plug to magnetize said screw, said screw contacting saidweight to hold the same above said spring arm, whereby removal of saidplug demagnetizes said screw to permit said weight to fall on saidspring arm to close said circuit and actuate an alarm.

2. The structure of claim 1 wherein said magnetic means comprises apermanent magnet mounted in a three prong plug after removal of theground prong thereof.

3. The structure of claim 2 wherein an open ended sleeve is secured tothe rear of said outlet box directly above said spring arm and directlybelow the extending end of said screw, and said weight comprises anelongated cylindrical steel member vertically slidable in said sleeve.

4. The structure of claim 3 wherein said permanent magnet directlycontacts the head of said screw to provide said means for contactingsaid screw with said magnetic means.

5. The structure of claim 3 wherein an extending mag netic wire issecured to the head of said screw exteriorly of said face plate andextends to a point in contact with said permanent magnet when said maleplug is,inserted in said female plug to provide said means forcontacting said screw with said magnetic means.

References Qited in the file of this patent UNITED STATES PATENTS1,992,255 Swadener Feb. 26, 1935 2,234,982 Ross Mar. 18, 1941 2,298,313Ross Oct. 13, 1942 2,573,920 McLeod Nov. 6, 1951 2,591,288 PitchfordApr. 1, 1952 2,681,443 Caulk June 15, 1954 2,969,445 Mitchell Jan. 24,1961

1. AN ALARM SYSTEM FOR PREVENTING THE UNAUTHORIZED REMOVAL OF ANELECTRICAL APPLIANCE, COMPRISING A WALL OUTLET BOX HAVING A FACE PLATE,A MAGNETIC SCREW SECURING SAID FACE PLATE TO THE BOX AND EXTENDTHERETHROUGH, AT LEAST ONE FEMALE SOCKET CARRIED BY SAID BOX, A FIXEDCONTACT MOUNTED ON SAID BOX INTERIORLY OF THE WALL RECEPTACLE, A SPRINGARM ABOVE SAID FIXED CONTACT, A MOVABLE CONTACT ON SAID SPRING ARM, ANALARM CIRCUIT ACTUABLE BY ENGAGEMENT OF SAID MOVABLE CONTACT WITH SAIDFIXED CONTACT, A MAGNETIC WEIGHT NORMALLY SUPPORTED ABOVE SAID SPRINGARM, A MALE PLUG CONNECTED TO AN ELECTRICAL APPLIANCE ENGAGEABLE IN SAIDFEMALE SOCKET, MAGNETIC MEANS CARRIED BY SAID MALE PLUG, AND MEANSCONTACTING SAID MAGNETIC SCREW WITH SAID MAGNETIC MEANS WHEN SAID MALEPLUG IS INSERTED IN SAID FEMALE PLUG TO MAGNETIZE SAID SCREW, SAID SCREWCONTACTING SAID WEIGHT TO HOLD THE SAME ABOVE SAID SPRING ARM, WHEREBYREMOVAL OF SAID PLUG DEMAGNETIZES SAID SCREW TO PERMIT SAID WEIGHT TOFALL ON SAID SPRING ARM TO CLOSE SAID CIRCUIT AND ACTUATE AN ALARM.